Arrangement for accommodating a scale in a positive engagement

ABSTRACT

An arrangement for accommodating a scale (2) of a length measuring device in a positive-locking engagement has a profile base (1) and lateral profile legs (4, 5) which are connected with the profile base so as to project away from it. A scale (2) is arranged between the profile legs (4; 5). The profile legs (4; 5) are made of elastic material and the profile base (1) is made of a longitudinally stable, bendable material. The profile legs (4; 5) can contain elastic sealing slats.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention is directed to an arrangement for receiving oraccommodating a scale in an interlocking or positive-locking engagementand can be used, for example, for measuring devices in machineconstruction.

2. Description of the Related Art

Numerous measurement devices are known from the prior art in which thescale is accommodated in an elongated hollow body (DE-C-25 05 587). Inthis case, the scale is generally connected with a hollow body by theintermediary of a resilient intermediate layer. The hollow bodies aremade from light metal, preferably aluminum.

In a great many constructions, especially for large measurement lengths,a graduated steel strip is used as a scale. This graduated strip isaccommodated in grooves or folds of the support body. A configuration ofthis kind in which the base or support body is constructed as asupporting hollow profile is known from DE-C-27 12 421.

Devices for measuring extensive lengths are realized in such a way thatportions of the support body which are advantageous with respect tolength are aligned and fixed on a machine component, wherein it is knownin general to arrange elastic seals between the individual portions inorder to compensate for thermal expansion. After the portion of thesupport body has been mounted, the measurement strip is drawn into thegroove of the support body and fastened. A corresponding practicalconstruction with a measurement strip support is known from the companybrochure "NC Linear Encoders", July 1994, published by the Heidenhaincompany. In this case, individual measurement strip support portionsmust be aligned on the machine component and fastened by screws forextensive measurement lengths.

All of these constructions have the disadvantage that the scale supportmust be fastened and aligned on the machine component in a cumbersomeassembling process which is very costly for extensive lengths.

OBJECT AND SUMMARY OF THE INVENTION

The primary object of the invention is to provide an arrangement inwhich a scale is held in a positive engagement such that the mounting ofthe scale support, e.g., on a machine tool, also for large measurementlengths, is achieved economically with respect to time and effort.

This object is met in accordance with the invention in an arrangement ofthe generic type for accommodating a measurement scale in a positiveengagement in that the profile legs are made of elastic or flexiblematerial and the profile base is formed of a longitudinally stable,bendable material.

In accordance with a preferred embodiment of the invention, thelongitudinally stable, bendable material is a metal strip.

In an advantageous further development of the invention, the profilelegs contain elastic sealing lamellae or sealing slats.

The profile legs are advantageously connected with the profile base byself-adhesive foil.

The profile legs and the profile base are advantageously enclosed byelastic sealing slats.

A simple and economical mounting of a scale body formed of a scale andprofile base on a machine tool is achieved by means of the solutionaccording to the invention. Beyond this, the solution according to theinvention enables efficient transport, also for purposes of servicing,since the scale body can be wound up in the case of extensivemeasurement lengths.

The invention will be described more fully in the following withreference to a schematic drawing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic illustration of the arrangement according tothe invention and;

FIGS. 2a), 2b), 2c) show additional embodiment forms of the arrangementaccording to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the arrangement which is shown schematically in FIG. 1, a scale 2,e.g., a graduated steel rule, is arranged on a profile base 1 made, forexample, from steel. The scale 2 can be constructed, with or without anintermediate layer 3, as an elastic adhesive layer or an oil filmresting on the profile base 1. The profile base 1 can be made of a metalstrip, for instance. Two profile legs 4, 5 which are made from elasticmaterial, e.g., polyurethane, are arranged laterally of the scale 2along its length in the longitudinal direction. The profile legs 4, 5are fastened to the profile base 1 by means of conventional connectiontechniques, e.g., by gluing, vulcanizing, spraying, etc., or by means ofself-adhesive foil.

The material of which the profile legs 4, 5 and profile base 1 arefabricated should preferably have a stiffness enabling them to be woundupon a base body with a radius r of 20-40 cm diameter, for example. Thesensing unit 7 is shown schematically. The sensing unit 7, which isnormally connected with a slide 10 ensuring the guidance of themeasurement device, slides in two elastic sealing slats 6 arranged inthe longitudinal direction. The scale 2 and the sensor of the sensingunit 7 are thus protected from harmful environmental influences. Sincethe scale 2 is uncoupled flexibly from the base body in small areas andthe profile legs and profile base bend easily, this arrangement can bewound up in its entirety, especially when used for large measurementlengths, and advantageously transported. In order to install or removethe overall arrangement in or on a machine component 8 with a planereceiving surface 9, the system need only be unrolled, inserted in thelongitudinal direction in recesses 12 which are formed, for instance, asgrooves or folds, and fixed therein.

The folds 11 arranged laterally at the profile legs and definingrecesses 11a ensure that the scale 2 will be held in a positiveengagement so as to be substantially free of play.

A spatially defined, rigid gluing or locking, not shown, forms a fixedassignment of position as a fixed point between the scale 2 and theprofile base.

This fixed point is preferably selected in such a way that it coincideswith the zero point or origin, not shown, of the machine coordinatesystem. The profile base 1 is likewise fixedly connected with themachine component 8 at this fixed point.

The lateral and vertical accommodation and orientation of the scale 2can be realized by means of recesses formed in the elastic profile legs4, 5.

FIGS. 2a) and 2b) contain embodiment forms for the configuration of theelastic profile legs 4, 5 with the sealing slats 6.

It will be seen from the embodiment forms in 2a) and 2c) that theelastic profile leg 4 and the sealing slat 6 are formed from one part in2c), whereas in 2a) the sealing slat 6 is arranged on or at the elasticprofile leg 4 by conventional connecting techniques, e.g., by gluing.

FIG. 2b) shows an advantageous construction of the invention in whichthe sealing slat 6 can be locked with the elastic profile leg 4 via apressure-type locking.

The elastic profile legs 5 have the same construction as the profilelegs 4, 5 and sealing slats 6 arranged in FIG. 1.

While the foregoing description and drawings represent the preferredembodiments of the present invention, it will be obvious to thoseskilled in the art that various changes and modifications may be madetherein without departing from the true spirit and scope of the presentinvention.

What is claimed is:
 1. A length measuring device, comprising a scale; aprofile base for supporting the scale; lateral profile legs connectedwith the profile base and projecting away therefrom for accommodatingthe scale on the profile base; and a space,wherein the profile base isformed of a longitudinally stable and bendable metal strip; wherein thelateral profile legs are made of an elastic material; wherein the scaleand the space are arranged between the profile legs; the space having adepth comprising a majority portion of a height of the lateral profilelegs from the profile base; and wherein both the metal strip and theelastic material have a stiffness enabling the profile legs and theprofile base to be wound up.
 2. The length measuring device according toclaim 1, wherein both the metal strip and the elastic material have astiffness enabling said profile legs and said profile base to be woundupon a base body with a radius of 20-40 cm.
 3. The length measuringdevice according to claim 1, wherein the scale is a graduated steelrule.
 4. The length measuring device according to claim 1, wherein thescale is mounted on the profile base by an adhesive layer.
 5. The lengthmeasuring device according to claim 1, wherein the scale is rested onthe profile base with an intermediate oil film.
 6. The length measuringdevice according to claim 1, wherein said profile legs are connected tosaid profile base by self-adhesive foil.
 7. The length measuring deviceaccording to claim 1, wherein said profile legs have a holding means forholding said scale in a positive engagement on said profile base whereinsaid holding means are folds.
 8. The length measuring device accordingto claim 1, wherein said profile legs have a holding means for holdingsaid scale in a positive engagement on said profile base, wherein saidholding means are recesses formed in said elastic profile legs.
 9. Thelength measuring device according to claim 1, wherein each said profilelegs contains an elastic sealing slat for protecting said scale and asensor of a sensing unit from environmental influences.
 10. The lengthmeasuring device according to claim 9, wherein each said profile leg andsaid corresponding sealing slat are formed from one part.
 11. The lengthmeasuring device according to claim 1, wherein said profile legs areconnected with said profile base by a self-adhesive foil.
 12. The lengthmeasuring device according to claim 1, wherein the scale is inserted, ina longitudinal direction, in recesses formed by respective folds of theprofile legs.
 13. In a length measuring device including a scale; aprofile base for supporting the scale; lateral profile legs connectedwith the profile base and projecting away therefrom for accommodatingthe scale on the profile base; and a space, wherein the scale and thespace are arranged between the profile legs, the space having a depthcomprising a majority portion of a height of the lateral profile legsfrom the profile base, the improvement comprising forming the profilelegs of an elastic material and forming the profile base of alongitudinally stable and bendable metal strip, both the elasticmaterial and the metal strip having a stiffness enabling the profilelegs and the profile base to be wound upon a base body with a radius of20-40 cm, and the profile legs forming laterally arranged means forholding the scale in a positive locking engagement with the profilebase.
 14. The improvement according to claim 13, wherein said scale is agraduated steel rule.
 15. The improvement according to claim 13, whereinsaid scale is mounted on said profile base by an adhesive layer.
 16. Theimprovement according to claim 13, wherein said scale is rested on saidprofile base with an intermediate oil firm.
 17. An arrangement,comprising a machine component having a plane receiving surface; and alength measuring device mounted on the receiving surface of the machinecomponent, the length measuring device including a scale; a profile basefor supporting the scale; lateral profile legs connected with theprofile base and projecting away therefrom for accommodating the scaleon the profile base; and a space, wherein the profile base is formed ofa longitudinally stable and bendable metal strip; wherein the lateralprofile legs are made of an elastic material; wherein the scale and thespace are arranged between the profile legs; wherein the space has adepth comprising a majority portion of a height of the lateral profilelegs from the profile base; andwherein both the metal strip and theelastic material have a stiffness enabling the profile legs and theprofile base to be wound up.
 18. An arrangement according to claim 17,wherein the machine component has recesses extending in a longitudinaldirection for receiving the profile base, the length measuring devicebeing unrolled before insertion of the profile base in the recesses.